1. Field of the Invention
The present invention relates to a method and a structure for mounting a magnetic head, and, more particularly, to a method and a structure for mounting a magnetic head which is applicable to a magnetic recorder or reproducer in an electronic camera system or the like.
2. Description of the Prior Art
Recently, there has been developed an attractive electronic camera system wherein an image pickup device, such as a charge coupled device (CCD), an image pickup tube or the like, is combined with a recording device employing, as a recording medium, an inexpensive magnetic disc having a comparatively higher memory capacity to photograph an object electronically and record it into the rotating magnetic disc and to reproduce an image by a television system or printer separately provided.
This type of magnetic disc for use in the electronic camera system, unlike a magnetic disc used in an ordinary magnetic recorder/reproducer, stores still or moving image information recorded therein in a high density and also rotates at a high speed. Therefore, a magnetic head, which is brought into contact with the magnetic disc to record into or reproduce from the magnetic disc, must be adjusted accurately in positioning with respect to the magnetic disc.
In view of the above-mentioned circumstances, the magnetic head used to record or reproduce the still image information and the like in the electronic camera or the like must be adjusted with respect to the magnetic disc in five respects: namely, (1) an amount of projection or extension, (2) an angle of inclination, (3) a shift in center alignment, (4) a shift in azimuth, and (5) a tilt. Among them, however, (2) the angle of inclination and (5) tilt may not be adjusted but can be dealt with only by means of so called "head ageing", when they are quite small. The abovementioned five types of adjustments will be sequentially described below in connection with FIGS. 1 to 3.
In FIG. 1, numeral 10 designates a magnetic disc, 12 represents a magnetic head to record into or reproduce from the magnetic disc 10, and 14 denotes a regulating plate located at a position opposed to the magnetic head 12 with the magnetic disc 10 between to place the magnetic disc 10 along the magnetic head 12. The magnetic head 12 must have an amount of projection or extension Ea within a predetermined range with respect to the magnetic disc 10. In order to perform further better recording and reproduction as well as to prevent the magnetic head and a recording medium from wearing, the magnetic head also requires a fine adjustment.
Also, in order to be able to obtain a reproduced image in a satisfactory manner even when one and the same recording medium is loaded into different reproducers, and when the recorder and reproducer are constructed separately that is, when a recording head and a reproducing head different from each other are used, it is necessary that an angle of inclination .theta.a of the magnetic head relative to the magnetic disc as shown in FIG. 1, an amount of shift Eb of the magnetic head relative to the center of the magnetic disc 10 and an angle of azimuth shift .theta.b thereof as shown in FIG. 2, and an angle of tilt .theta.c of the magnetic head 12 with respect to the magnetic disc 10 as shown in FIG. 3 remain within predetermined interchangeable ranges, respectively.
In a conventional structure for mounting a magnetic head, a plurality of shims different from one another in thickness are located on a head carriage with a magnetic head previously fixed thereto so as to be able to adjust the height thereof, and, after such height adjustment, a head mounting plate is attached to the head carriage by an adhesive. In the conventional magnetic head mounting structure, however, since the head mounting plate is in surface-to-surface contact with the head carriage, when the thickness of the adhesive layer is equal to 100 .mu.m or more, then temperature variations or variations due to shrinkage during hardening may put the magnetic head out of place. Also, when the magnetic head is mounted using the shims, it takes time to insert the shims. Further, the above-mentioned conventional head mount structure is disadvantageous in that the machining accuracies of the shims have a great effect on the mounting accuracy of the magnetic head.